Angle and tilt mechanism for bulldozer

ABSTRACT

A bulldozer blade is mounted on the central front part of a Cframe so as to permit angling about a generally vertical axis by adjusting the position of the connecting points of braces and struts extending between the rear of the dozer blade and the legs of the C-frame. The dozer blade is tilted aboout a generally longitudinal axis by changing the length of extensible struts connected between the bottom rear of the dozer blade and the Cframe legs. The upper rear portion of the blade is interconnected to the C-frame by a link which serves to compensate for predetermined motion occuring between the dozer blade and the Cframe as dozer blade is tilted. A blade angling mechanism includes a pair of hydraulic jacks disposed telesopically within a pair of cylindrical members which are guided on longitudinal tracks on the legs of the C-frame to avoid side loading of the hydraulic jacks.

1 July 31, 1973 ANGLE AND TILT MECHANISM FOR BULLDOZER [75] inventor: Harvey W. Rockwell, Springfield, Ill.

[73] Assignee: Allis-Chalmers Corporation,

Milwaukee, Wis.

[22} Filed: Apr. 7, 1972 [21] Appl. No.: 241,949

Primary Examiner-Robert E. Pulfrey Assistant Examiner-Stephen C. Pellegrino Att0rneyCharles L. Schwab et al.

[5 7] ABSTRACT A bulldozer blade is mounted on the central front part of a C-frame so as to permit angling about a generally vertical axis by adjusting the position of the connecting points of braces and struts extending between the rear of the dozer blade and the legs of the C-t'rame. The dozer blade is tilted aboout a generally longitudinal axis by changing the length of extensible struts connected between the bottom rear of the dozer blade and the C- frame legs. The upper rear portion of the blade is interconnected to the C-frame by a link which serves to compensate for predetermined motion occuring between the dozer blade and the C-frame as dozer blade is tilted. A blade angling mechanism includes a pair of hydraulic jacks disposed telesopically within a pair of cylindrical members which are guided on longitudinal tracks on the legs of the C-frame to avoid side loading of the hydraulic jacks.

12 Claims, 11 Drawing Figures Patented July 31, 1973 7 Sheets-Sheet l Patented July 31, 1973 '7 Sheets-Sheet 73 Patented July 31 '7 Sheets-Sheet g ANGLE AND TILT MECHANISM FOR BULLDOZER BACKGROUND OF THE INVENTION Heretofore, it has been suggested that a bulldozer blade be mounted on a C-frame for angling and tilting. Earlier constructions include those shown in U.S. Pat. Nos. 2,943,407 and 3,386,519, both of which disclose hydraulically angled blades with provision for tilting the blade by extending and contracting extensible links interconnected between the laterally opposite top ends of the blade and the rear parts of braces interconnected between the lower end of the blade and a shiftable pivot on the C-frame legs. These prior constructions do not have adequate provisions for handling stress producing motions created when the blade is tilted.

BRIEF DESCRIPTION OF THE INVENTION The present invention not only provides a novel angle and tilt dozer construction in the manner of mounting the hydraulic cylinders for angling the blade but also compensates for the stress producing motion created on tilting the dozer blade. This is achieved by locating the pivot connection between the dozer and C-frame at the lower central rear of the dozer blade and by making the connection between the upper transverse ends of the dozer blade and the C-frame fixed links, and by making the lower links between the lower transverse ends of the dozer blade and the C-frame extensible links. Additionally when employing hydraulically actuated jacks to angle the blade, the present invention provides a longitudinal swing link between the upper rear central part of the blade and the front of the C-frame. This provides stability for mounting the blade and allows the top of the dozer to adjust its fore and aft position relative to the C-frame as the dozer is tilted thus avoiding undesirable build up of stresses that otherwise would occur.

BRIEF DESCRIPTION OF THE DRAWINGS Various features and embodiments of the present invention are shown in the drawings in which:

FIG. 1 is a side view of a tractor on which a bulldozer incorporating the present invention is mounted;

FIG. 2 is a section view taken along the line II-II in FIG. 4;

FIG. 3 is a section view taken along the line III--III in FIG. 1;

FIG. 4 is a top view of the tractor and dozer shown in FIG. 1 with the dozer blade in an angled position;

FIG. 5 is a perspective view of the tractor and dozer incorporating the present invention with the dozer blade angled and tilted downwardly at the left side of the tractor;

FIG. 6 is a view similar to FIG. 5 except the blade has been tilted upwardly at the left side of the tractor;

FIG. 7 is a perspective view of the tractor and dozer of the present invention with the blade in a straight (nonangled) position and tilted downwardly at the left side of the tractor;

FIG. 8 is a side view of a tractor showing a modified form of the present invention;

FIG. 9 is a section view showing the pivot connection between the C-frame and the dozer blade of FIG. 8;

FIG. 10 is a partial showing of the tilt mechanism of FIG. 8 with the lower extensible link replaced by a double acting hydraulic jack; and

FIG. 11 is a side view of a tractor showing another embodiment of the present invention.

Referring to FIGS. 1 through 4, a crawler tractor 21 is provided with a pair of endless tracks 22, 22 mounted on track frames 23, 23' which are connected, respectively, to opposite lateral sides of a main frame 24 for vertical swinging movement about a transverse pivot axis 26. A C-frame 27 is pivotally connected to the track frames of the tractor on a transverse pivot axis 28. This last mentioned connection being between the rear ends of the leg portions 74, 74 of the C-frame 27 and pivot balls 25, 25 secured to the track frames 23, 23'.

The central lower rear of a dozer blade 31 is pivotally connected to the bridging portion 73 of the C-frame 27 by a spherical pivot connection 32 (See FIG. 2). The upper central rear of the dozer blade 31 is interconnected to an upstanding portion 33 of the bridging portion 73 of the C-frame 27 by a longitudinal link 34 having universal connections 36, 37 therewith. Pivot connection 36 is vertically aligned with the lower pivot connection 32. The left side of the dozer blade 31 has an upper rear transverse end part universally connected to a front end of a brace 38. The rear end of the brace 38 is pivotally connected to the C-frame leg portion 74 by pivot means in the form of a ball and socket connection 39. The ball 41 of the ball and socket connection 39 is rigidly secured to a housing in the form of cylindrical member 42 which, as shown in FIG. 3, is in turn connected to the leg portion 74 of the C-frame 27 through a longitudinal guide track 44. The guide track 44 coacts with grooves 46, 47 formed in downwardly extending side walls SI, 52 of cylindrical member 42. An extensible strut mechanism 56 is interposed between the lower rear transverse end portion at the left side of the dozer blade 31 and the pivot means 39. The extensible strut mechanism 56, as illustrated in FIG. 1, includes a longitudinal link 57 having its forward end pivotally connected to the rear of the dozer blade 31 by a universal joint 60. The rear end of the link 57 is pivotally connected at its rear end to the lower end of a vertical disclosed lever 58 by a pin 59. The lever 58 is pivotally connected intermediate its upper and lower ends to the brace 38 by a pivot pin 61. In order to extend and retract the strut mechanism, a double acting hydraulic jack 62 is interposed between the upper end of the lever 58 and the forward end of the brace 38. The double acting hydraulic jack 62 includes a cylinder 63 having its closed end pivotally connected to the brace 38 by a pivot pin 64 and a piston 65 with a rod portion 66 extending from the open end of the cylinder 63 and pivotally connected to the upper end of the vertical lever 58 by a pivot pin 67. The placement of the jack 62 in its high position above the brace 38 places it out of the dirt and in a relatively protected location.

Referring to FIGS. 1 and 4, the C-frame 27 is swingable vertically about its transverse pivot axis 28 by a pair of double acting hydraulic jacks 71, 71'. The double acting hydraulic jacks 71, 71 have cylinders 72, 72 which are gimbel connected to the frame 24 of the tractor and have piston rods 75, 75' pivotally connected to the bridging portion 73 of the C-frame. As also shown in FIGS. 1 and 4, the pivot means 39 and the cylindrical member 42 to which it is rigidly attached is shifted longitudinally on the guide track 44 by a single acting jack 81 which has its cylinder 82 pivotally connected at its closed end to an upstanding bracket 83 on the rear end of the C-frame leg portion 74 by a pin 84. The piston 86 of the single acting jack 82 has its free end pivotally connected to the front end of the cylindrical member 42 by a pivot pin 87. Thus it is seen that the side thrust from the pivot means 39 is taken by the cylindrical member 42 and guide track 44 rather than the jack 81. The hydraulic jack 81 will not be subjected to side thrust since it fits loosely within cylindrical member 42. In FIG. 4, it will be noted that the jack 81 has been expanded and the jack 81 has been contracted to thereby angle the blade 31 as illustrated. By operation of the jacks 81, 81 with conventional controls, not shown, an infinite number of angled positions can be obtained. The brace 38 and extensible strut mechanism 56' are a reverse image of the brace 38 and strut mechanism 56. So too, the guide track 44', jack 81' and cylindrical member 42' at the right side of the dozer are reverse images of track 44, jack 81 and member 42.

In FIG. 5, the angling jack 81 has been retracted and the angling jack 81' has been expanded to angle the dozer blade. Also, the tilt jack 62 has been expanded to extend the strut mechanism 56 and the tilt jack 62 has been contracted to contract the extensible strut mechanism 56. This forces the left end of the blade, as viewed from the operators station 101, down and thus the blade cuts deeper on the near end than the far end as viewed in FIG. 5. When the blade is tilted about a substantially longitudinal axis passing through spherical pivot connection 32, the fixed length braces 38, 38' will force the upper part of the blade rearwardly. The link 34 and its pivot connections 36, 37 are so proportioned as to allow the top of the blade to move rearwardly, as the link 34 swings on pivot 37, the same distance as the top is required to move because of the fixed length braces 38, 38'. The link 34 actually predetermines the fore and aft movement of the top of the blade 31.

FIG. 6 shows the blade 32 angled as in FIG. but tilted upwardly on the left side, as viewed by the operator. As illustrated, the tilt jack 62 is contracted to retract extensible strut mechanism 56 and tilt jack 62' is extended to extend strut mechanism 56'. In this condition, the right hand end of the blade, as viewed from the operator's station 101, is cutting deeper than the left end.

FIG. 7 shows the blade 31 in a nonangled condition but tilted to cut deeper on the left end than on the right, as viewed by the operator. Note that again the link 34 has swung to the same lateral side that the blade is tilted down, thus allowing the top of the blade to move rearwardly compensating for the distance the top of the blade must move rearwardly due to the fixed length braces 38, 38' interconnecting the top opposite ends of the blade and the leg portions 74, 74' of the C-frame 27.

FIG. 3 is a side view of a modified form of the present invention. The blade 131 may be angled by connecting the pivot means 139 at one of three brackets 142, 143, 144 to the leg 174 of C-frame 127. Tilting is accomplished by extending strut mechanism 156 interconnected between the blade 131 and the rear end of fixed length brace 138, the latter being connected to the C- frame by pivot means 139 in the form of a ball and socket joint. It will be noted that the longitudinal link 34 has been eliminated in the FIG. 8 embodiment. This is possible because the dozer construction retains geometric stability and is free of stress bulld-up when tilted because the center pivot connection 132, shown in FIG. 9, is of the universal type and is located substantially removed in a vertical direction from the connection between the brace 138 and the blade. As the strut mechanisms are adjusted, the braces predetermine the pitch of the blade, that is, the fore and aft swinging movement of the blade about its lower connection 132.

In FIG. 10 a double acting hydraulic jack 256 is shown replacing the mechanically adjustable strut mechanism 156 of the FIG. 8 embodiment of the invention.

The embodiment of the invention shown in FIG. 11 is similar to that shown in FIG. 8 except that the brace 38 and strut mechanism 56 of the FIG. I embodiment replace the brace 138 and strut mechanism 156. This embodiment is preferred to that of FIG. 10 because the jack 62 is out of the dirt. It is, however, a more expensive adjustable strut mechanism and where cost is a dctermining factor, the lower mounted jack 256 of the embodiment shown in FIG. 10 may be preferred.

Although only the left hand side of the dozers shown in FIGS. 8, l0 and 11 have been described, it should be understood that the right hand side is a reverse image of the left hand side.

From the foregoing description, it is apparent that a novel and useful dozer with angle and tilt features has been invented. A variety of angle and tilt dozers can be offered to the customer using similar blades and C- frames. The manually adjusted dozer of FIG. 8 would be least costly of the various versions illustrated but not as readily adjusted as the dozer shown in FIG. I.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. In a bulldozer for a tractor, the combination comprising:

a C-frame presenting leg portions adapted for pivotal connection to opposite sides of a tractor for vertical swinging movement on a transverse axis and presenting a bridging portion between said leg portions adapted for disposition at the front of said tractor,

a transversely extending dozer blade,

means connecting the central lower rear of said blade to said bridging portion in a manner permitting said blade to be angled and tilted'relative to said C- frame,

a pair of braces having corresponding front ends pivotally connected, respectively, to transversely opposite upper rear ends of said blade,

a pair of extensible strut mechanisms having corresponding front ends pivotally connected, respectively, to transversely opposite lower rear ends of said blade,

pivot means connecting the rear portions of said brace and strut mechanism disposed at one end of said blade to one leg of said C-frame,

pivot means connecting the rear portions of said brace and strut mechanism disposed at the other end of said blade to the other leg of said C-frame,

means permitting selective longitudinal positioning of said pivot means relative to said legs of said C- frame whereby said blade may be selectively angled, and

a longitudinally extending link pivotally connected at its front end to the top central rear of said blade and pivotally connected at its rear end to said bridging portion of said C-frame at a point spaced substantially above the points at which said struts are connected to said blade.

2. The structure of claim 1 and further comprising means for adjusting the position of said pivot means relative to said legs including fluid operated jacks operatively interposed between said pivot means and said legs, respectively.

3. The structure of claim 2 wherein each of said strut mechanisms includes a fluid operated jack.

4. The structure of claim 3 wherein said strut mechanisms include corresponding parts pivotally connected to said braces, respectively.

5. The structure of claim 4 wherein each of said strut mechanisms includes a longitudinal link part having a front end constitut' ing said front end of said strut mechanism,

an upstanding lever part having its middle portion pivotally connected to the brace on the corresponding end of said blade and its bottom portion pivotally connected to the rear of said link part, and

an extensible link part including said fluid operated jack interconnected between said associated brace and the top portion of said lever.

6. The structure of claim 1 wherein said means permitting selective longitudinal positioning of said pivot means includes a pair of housing members to which said pivot means are, respectively, secured,

means for longitudinally guiding said housing members on said leg portions, respectively, and

a pair of fluid operated jacks disposed at least partially within and in telescoping relation to said housing members and having their cylinder components connected, respectively, to said leg portions and their piston components connected, respectively, to said housing members.

7. The structure of claim 6 wherein said strut mechanisms include corresponding parts pivotally connected to said braces. I

8. The structure of claim 7 wherein said strut mechanisms each include a fluid operating jack.

9. The structure of claim 8 wherein each of said strut mechanisms includes a longitudinal link part having a front end constituting said front end of said strut mechanism,

an upstanding lever part having its middle portion pivotally connected to the brace on the corresponding end of said blade and its bottom portion pivotally connected to the rear of said link part, and

an extensible link part including said fluid operated jack interconnected between said associated brace and the top portion of said lever.

10. In a bulldozer for a tractor, the combination comprising:

a C-frame presenting leg portions adapted for pivotal connection to opposite sides of a tractor for vertical swinging movement on a transverse axis and presenting a bridging portion between said leg portions adapted for disposition at the front of said tractor,

a transversely extending dozer blade,

means connecting the central lower rear of said blade to said bridging portion in a manner permitting said blade to be angled and tilted relative to said C- frame,

a pair of braces having corresponding front ends pivotally connected, respectively, to transversely opposite upper rear ends of said blade,

pivot means connecting, respectively, the rear portions of said braces to said legs of said C-frame, and

a pair of extensible strut mechanisms having corresponding link parts pivotally connected, re-

spectively, to transversely opposite lower rear ends of said blade,

a pair of upstanding lever parts with middle portions pivotally connected, respectively, to said braces and with bottom portions pivotally connected, respectively, to the rear ends of said link parts, and

a pair of fluid operated jackshaving corresponding ends pivotally connected, respectively, to said braces and the top portions of said levers.

11. The structure set forthin claim 10 and further comprising means permitting selective longitudinal positioning of said pivot means relative to said legs of said C-frame whereby said blade may be selectively angled.

12. The structure of claim 11 wherein said fluid operated jacks are disposed above said braces.

i i I. ll! 

1. In a bulldozer for a tractor, the combination comprising: a C-frame presenting leg portions adapted for pivotal connection to opposite sides of a tractor for vertical swinging movement on a transverse axis and presenting a bridging portion between said leg portions adapted for disposition at the front of said tractor, a transversely extending dozer blade, means connecting the central lower rear of said blade to said bridging portion in a manner permitting said blade to be angled and tilted relative to said C-frame, a pair of braces having corresponding front ends pivotally connected, respectively, to transversely opposite upper rear ends of said blade, a pair of extensible strut mechanisms having corresponding front ends pivotally connected, respectively, to transversely opposite lower rear ends of said blade, pivot means connecting the rear portions of said brace and strut mechanism disposed at one end of said blade to one leg of said C-frame, pivot means connecting the rear portions of said brace and strut mechanism disposed at the other end of said blade to the other leg of said C-frame, means permitting selective longitudinal positioning of said pivot means relative to said legs of said C-frame whereby said blade may be selectively angled, and a longitudinally extending link pivotally connected at its front end to the top central rear of said blade and pivotally connected at its rear end to said bridging portion of said Cframe at a point spaced substantially above the points at which said struts are connected to said blade.
 2. The structure of claim 1 and further comprising means for adjusting the position of said pivot means relative to said legs including fluid operated jacks operatively interposed between said pivot means and said legs, respectively.
 3. The structure of claim 2 wherein each of said strut mechanisms includes a fluid operated jack.
 4. The structure of claim 3 wherein said strut mechanisms include corresponding parts pivotally connected to said braces, respectively.
 5. The structure of claim 4 wherein each of said strut mechanisms includes a longitudinal link part having a front end constituting said front end of said strut mechanism, an upstanding lever part having its middle portion pivotally connected to the brace on the corresponding end of said blade and itS bottom portion pivotally connected to the rear of said link part, and an extensible link part including said fluid operated jack interconnected between said associated brace and the top portion of said lever.
 6. The structure of claim 1 wherein said means permitting selective longitudinal positioning of said pivot means includes a pair of housing members to which said pivot means are, respectively, secured, means for longitudinally guiding said housing members on said leg portions, respectively, and a pair of fluid operated jacks disposed at least partially within and in telescoping relation to said housing members and having their cylinder components connected, respectively, to said leg portions and their piston components connected, respectively, to said housing members.
 7. The structure of claim 6 wherein said strut mechanisms include corresponding parts pivotally connected to said braces.
 8. The structure of claim 7 wherein said strut mechanisms each include a fluid operating jack.
 9. The structure of claim 8 wherein each of said strut mechanisms includes a longitudinal link part having a front end constituting said front end of said strut mechanism, an upstanding lever part having its middle portion pivotally connected to the brace on the corresponding end of said blade and its bottom portion pivotally connected to the rear of said link part, and an extensible link part including said fluid operated jack interconnected between said associated brace and the top portion of said lever.
 10. In a bulldozer for a tractor, the combination comprising: a C-frame presenting leg portions adapted for pivotal connection to opposite sides of a tractor for vertical swinging movement on a transverse axis and presenting a bridging portion between said leg portions adapted for disposition at the front of said tractor, a transversely extending dozer blade, means connecting the central lower rear of said blade to said bridging portion in a manner permitting said blade to be angled and tilted relative to said C-frame, a pair of braces having corresponding front ends pivotally connected, respectively, to transversely opposite upper rear ends of said blade, pivot means connecting, respectively, the rear portions of said braces to said legs of said C-frame, and a pair of extensible strut mechanisms having corresponding link parts pivotally connected, respectively, to transversely opposite lower rear ends of said blade, a pair of upstanding lever parts with middle portions pivotally connected, respectively, to said braces and with bottom portions pivotally connected, respectively, to the rear ends of said link parts, and a pair of fluid operated jacks having corresponding ends pivotally connected, respectively, to said braces and the top portions of said levers.
 11. The structure set forth in claim 10 and further comprising means permitting selective longitudinal positioning of said pivot means relative to said legs of said C-frame whereby said blade may be selectively angled.
 12. The structure of claim 11 wherein said fluid operated jacks are disposed above said braces. 